package org.apache.maven.lifecycle.internal;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import org.apache.maven.execution.MavenSession;
import org.apache.maven.project.MavenProject;
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.annotations.Requirement;
import org.codehaus.plexus.logging.Logger;

import java.util.List;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;

/**
 * Builds the full lifecycle in weave-mode (phase by phase as opposed to project-by-project)
 * 
 * @since 3.0
 * @author Kristian Rosenvold Builds one or more lifecycles for a full module
 *         <p/>
 *         NOTE: This class is not part of any public api and can be changed or deleted without
 *         prior notice.
 */
@Component(role = LifecycleThreadedBuilder.class)
public class LifecycleThreadedBuilder {

  @Requirement
  private Logger logger;

  @Requirement
  private LifecycleModuleBuilder lifecycleModuleBuilder;

  public LifecycleThreadedBuilder() {
  }

  public void build(MavenSession session, ReactorContext reactorContext, ProjectBuildList projectBuilds,
      List<TaskSegment> currentTaskSegment, ConcurrencyDependencyGraph analyzer,
      CompletionService<ProjectSegment> service) {

    // Currently disabled
    ThreadOutputMuxer muxer = null; // new ThreadOutputMuxer( analyzer.getProjectBuilds(),
                                    // System.out );

    for (TaskSegment taskSegment : currentTaskSegment) {
      Map<MavenProject, ProjectSegment> projectBuildMap = projectBuilds.selectSegment(taskSegment);
      try {
        multiThreadedProjectTaskSegmentBuild(analyzer, reactorContext, session, service, taskSegment, projectBuildMap,
            muxer);
        if (reactorContext.getReactorBuildStatus().isHalted()) {
          break;
        }
      } catch (Exception e) {
        session.getResult().addException(e);
        break;
      }

    }
  }

  private void multiThreadedProjectTaskSegmentBuild(ConcurrencyDependencyGraph analyzer, ReactorContext reactorContext,
      MavenSession rootSession, CompletionService<ProjectSegment> service, TaskSegment taskSegment,
      Map<MavenProject, ProjectSegment> projectBuildList, ThreadOutputMuxer muxer) {

    // schedule independent projects
    for (MavenProject mavenProject : analyzer.getRootSchedulableBuilds()) {
      ProjectSegment projectSegment = projectBuildList.get(mavenProject);
      logger.debug("Scheduling: " + projectSegment.getProject());
      Callable<ProjectSegment> cb = createBuildCallable(rootSession, projectSegment, reactorContext, taskSegment,
          muxer);
      service.submit(cb);
    }

    // for each finished project
    for (int i = 0; i < analyzer.getNumberOfBuilds(); i++) {
      try {
        ProjectSegment projectBuild = service.take().get();
        if (reactorContext.getReactorBuildStatus().isHalted()) {
          break;
        }
        final List<MavenProject> newItemsThatCanBeBuilt = analyzer.markAsFinished(projectBuild.getProject());
        for (MavenProject mavenProject : newItemsThatCanBeBuilt) {
          ProjectSegment scheduledDependent = projectBuildList.get(mavenProject);
          logger.debug("Scheduling: " + scheduledDependent);
          Callable<ProjectSegment> cb = createBuildCallable(rootSession, scheduledDependent, reactorContext,
              taskSegment, muxer);
          service.submit(cb);
        }
      } catch (InterruptedException e) {
        rootSession.getResult().addException(e);
        break;
      } catch (ExecutionException e) {
        rootSession.getResult().addException(e);
        break;
      }
    }

    // cancel outstanding builds (if any) - this can happen if an exception is thrown in above block

    Future<ProjectSegment> unprocessed;
    while ((unprocessed = service.poll()) != null) {
      try {
        unprocessed.get();
      } catch (InterruptedException e) {
        throw new RuntimeException(e);
      } catch (ExecutionException e) {
        throw new RuntimeException(e);
      }
    }
  }

  private Callable<ProjectSegment> createBuildCallable(final MavenSession rootSession,
      final ProjectSegment projectBuild, final ReactorContext reactorContext, final TaskSegment taskSegment,
      final ThreadOutputMuxer muxer) {
    return new Callable<ProjectSegment>() {
      public ProjectSegment call() {
        // muxer.associateThreadWithProjectSegment( projectBuild );
        lifecycleModuleBuilder.buildProject(projectBuild.getSession(), rootSession, reactorContext,
            projectBuild.getProject(), taskSegment);
        // muxer.setThisModuleComplete( projectBuild );

        return projectBuild;
      }
    };
  }
}